With regard to 5-aminolevulinic acid, various uses have been proposed in various fields. For example, the compound is known to be useful for VB12 production, heme enzyme production, microbial culturing, porphyrin production and the like in the field of microbes/fermentation, for infectious disease treatment (Non-Patent Document 1), sterilization, Haemophilus diagnosis, derivative materials, depilation, rheumatism therapy (Non-Patent Document 2), cancer therapy (Non-Patent Document 3), thrombus therapy (Non-Patent Document 4), diagnosis during cancer operation (Non-Patent Document 5), animal cell culture, UV cut, heme metabolism research, hair care, diagnosis of heavy metal poisoning and porphyria, anemia prevention, and the like in the field of animal/medical care, and for agricultural chemicals and the like in the field of plants.
5-Aminolevulinic acid phosphate which is phosphate of the acid is found as a substance which overcomes problems in hydrochloride thereof which has been only known as the salt until that time and exhibits excellent effects such as odorless, low irritation, and high permeability into skin, so that the phosphate is suitable for transdermal administration and oral administration and also is useful as a photodynamic therapy and a photodynamic diagnostic agent (Patent Document 1). In Patent Document 1, 5-aminolevulinic acid phosphate was obtained as a solid precipitated by eluting 5-aminolevulinic acid adsorbed on an ion-exchange resin with aqueous ammonia, adding phosphoric acid to the resultant eluate, and then adding acetone thereto. It is also disclosed in Patent Document 2 that 5-aminolevulinic acid phosphate has properties suitable for the use of a photochemical therapy.
The agents such as pharmaceuticals and agricultural chemicals are frequently constrained to be stored for a long period of time and sometimes absorb moisture from the atmosphere during the storage. As a result, degradation occurs and thus a certain quality as pharmaceuticals and agricultural chemicals cannot be maintained, so that a high moisture absorption resistance is required. Moreover, there are many cases where heat sterilization is necessary and hence a high stability against heat treatment is also required.    Patent Document 1: WO2005/100300 pamphlet    Patent Document 2: WO2005/092838 pamphlet    Non-Patent Document 1: Peter W. et al., J. Am. Acad. Dermatol., 31, 678-680 (1994)    Non-Patent Document 2: Kenneth T., U.S. Pat. No. 5,368,841 (1994)    Non-Patent Document 3: Hillemanns P. et al., Int. J. Cancer, 85, 649-653 (2000)    Non-Patent Document 4: Ichiro Yamada et al., Abstracts of Papers, China-Japan Congress of Plastic Surgery (1988)    Non-Patent Document 5: Kamasaki N. et al., Journal of Japan Society for Laser Medicine, 22, 255-262 (2001)